2004 4.6L DOHC Service Mods

Yes, I still own my ’05 GT (28k miles) and I picked up a low mileage ’04 Marauder (41k miles) at the end of March. I live in the Charlotte, NC area and am looking for a shop to perform the rear cylinder head cooling modification, J-mod to the transmission and the tail housing lube modification to the transmission. I’m told the ’03 and ’04 Mach 1s were recommended for these service mods also. The Mercury Marauder board recommends a couple of shops NW of Atlanta but I would think there is someone in the Charlotte Metro who does this work. Thanks.